US Patent 7118903 L-methionine $g(g)-lyase with modified function

An L-methionine γ-lyase having modified function which is obtained by structurally stabilizing natural L-methionine γ-lyase by analyzing the structure of crystals thereof by using X-ray, estimating an amino acid sequence concerning its substrate specificity and varying amino acid residue thereof; enzymes comprising a protein constituting the L-methionine γ-lyase having modified function or its multimer (preferably its tetramer); DNA sequences encoding these enzymes; a process for producing these enzymes; and medicinal preparations (preferably anticancer agent) containing these enzymes.